Hell's Bells
by Takara Phoenix
Summary: Sequel to "The A and O of Love"! Years after the war, Magnus, Alec and Jace should get the chance to relax and kick back. But then Jace realizes he's pregnant and starts freaking out about how his mates will take the news. alpha!Magnus/beta!Alec/omega!Jace slashy threesome - two versions online, one with the side-pairings Lyzzy & Climon, one with Simon/Isabelle/Clary
1. New Climon & Lyzzy Canon

Malace || Shadowhunters || Malace || Hell's Bells || Malace || Shadowhunters || Malace

Title: Hell's Bells – How to Care for Your Pregnant Omega

Fandom: Shadowhunters: The Mortal Instruments

Disclaimer: All rights to the Shadowhunters reserved to Ed Decter, the books the Shadowhunters is based off and its characters belong to Cassandra Clare. This fanfiction on the other hand is entirely mine. No money is made with this, though reviews are more than welcomed.

Warnings: shounen-ai, ABO-verse, mpreg, pregnancy, fluff, family fluff, hurt/comfort, adoption, shoujo-ai, hetero

Main Pairing: Magnus/Alec/Jace

Side Pairings: Simon/Clary, Lydia/Isabelle

Shadowhunters Characters: Jonathan Christopher 'Jace' Wayland, Magnus Bane, Alexander Gideon 'Alec' Lightwood, Isabelle Sophia 'Izzy' Lightwood, Lydia Branwell, Clarissa Adele 'Clary' Fray, Simon Lewis, Madzie, Victor Aldertree

Own Characters of the Next Generation:

 _Magnus/Alec/Jace_ : Belinda Isabelle Bane

 _Lydia/Isabelle_ : Laura Charlotte Lightwood, Henry Alexander Lightwood

 _Simon/Clary_ : Dorothea Elaine Lewis

Summary: Jace has been feeling like shit, until he realizes that he's pregnant. With all the stress, ironically because Clary is pregnant and he's helping out, he completely forgot to get his shots before his last heat and now he's pregnant. He doesn't even know if Alec and Magnus want to have children. What if they don't? Will Magnus and Alec catch on and comfort their omega?

 **Hell's Bells**

 _How to Care for Your Pregnant Omega_

Jace's heart was beating too fast. It was hammering against his ribs like it wanted to break out. He couldn't believe it. Then again, the last six pregnancy tests he had taken all showed the same thing.

Jace was pregnant with Alec's baby.

He knew it could only be Alec's, because Magnus was a warlock and warlocks were sterile. Which was kind of why the threesome had never brought up the matter of children before. Granted, when the three of them had gotten together, they had still been in the middle of the war against Valentine and that was just really not the right kind of time or environment to have a baby, or to be pregnant. Jace _needed_ to be there when they caught Valentine and ended his madness, he would not have been able to live with himself if he had been forced to sit it out because he was pregnant.

But he had also never planned for it to be like this. Well, no one ever planned for an unplanned pregnancy, hence the name, huh? Jace glared viciously at the pregnancy test and threw it to its kin.

He had been feeling like shit for the past two weeks. Nauseous and throwing up a lot, moody and with weird aches. He tried to deny it at first, because it couldn't possibly be. But then, then he started to wonder. Had he _really_ gotten his contraceptive shots before his last heat? Had he really? Or had he maybe forgotten about it? Perhaps he had. He had been kind of busy with everything lately. Sure, Valentine was taken care of, but now they had to clean up after Valentine. And then Madzie had kind of been living with them and since Magnus was so busy as the High Warlock – because Madzie was not the only orphan and abandoned warlock left in the wake of Valentine's attempted genocide – and Alec was now acting head of the Institute, which meant that it kind of fell to Jace to take care of Madzie most of the time. Which kind of figured, considering he was an omega and omegas took care of the children. Oh. What... if now that he actually _was_ pregnant, his mates would want him to stay at home? Jace frowned displeased and shook his head.

No. No, Magnus was a good alpha and he would not force Jace to be a stay-at-home omega. Those were just the stupid hormones talking. Magnus had never been bothered that Jace, as an omega, was out in the field and putting himself into danger, even though _many_ magical communities still thought that omegas should not be put at risk like that; Shadowhunters included. And Alec was the perfect beta, he knew exactly how to balance Magnus and Jace out and he would totally intervene even on the non-existent event that Magnus would be _that_ old-fashioned.

Anyway. Back on topic. Jace was pregnant with Alec's child and he had no idea how it had happened. Well. He knew _how_ , considering that his heats shared with his beta and his alpha were _more_ than just memorable. But how exactly had he forgotten to get his shots? Was it because he was overwhelmed with Madzie? And if he was already overwhelmed with her, how in the world was he supposed to handle a _baby_? Had it maybe been Isabelle? Ever since Jace and Alec got to be uncles last year, Jace had to admit that he felt more inclined toward a baby. Laura Charlotte Lightwood was the cutest little thing on this planet.

Or had it been because of Clary? Lately, he had been spending a lot of his time with Clary, because she was pregnant. And the pregnant female omega was being very clinging with her 'brother' since then, omega-bonding and seeking comfort from her self-chosen family. Even after Valentine's lies had been exposed, Clary didn't care – she had started seeing Jace as her brother and she was not about to stop just because their shared blood had been a lie. Jace found himself clinging onto that love, that piece of family. Which was why he was so willing to accompany her everywhere, go baby-toys and baby-furniture and baby-clothes shopping with her. He helped Simon, who was _utterly_ helpless, baby-proving the apartment and putting together the furniture. And all of that on top of taking care of Madzie and still being an active Shadowhunter. He was kind of stretched thin, even if he wasn't the High Warlock of Brooklyn or the head of the Institute. So maybe, perhaps, he had kind of forgotten the shots. Had canceled the appointment because something else had come up and he had forgotten to reschedule it?

Or had he subconsciously... just not gotten them? Had his sub-conscience chosen not to reschedule the appointment, because seeing Clary glow like that, seeing Clary be doted on by her alpha, seeing how proud and strong Simon could be now for his pregnant omega... Jace would be lying if he'd say that he didn't kind of crave that too. Now that the war was over, now that he actually had two mates who loved him and who he loved, he had a... family. He had an actual family and he wanted _more_ of it. He loved being 'uncle Jace' and if he was being very honest, he couldn't wait to be 'mom'.

So maybe he had forgotten it kind of on purpose without meaning to? If that made sense?

Jace's eyes widened as panic set in once more. What if Alec and Magnus thought he had done it fully on purpose? What if they didn't _want_ a baby? At all? Or just not right now?

He couldn't deal with all of this. It was just too much.

/2 Weeks Later\

Jace was curled together in the corner of the couch, next to Clary. She was already showing, a hand resting on her slightly bulging stomach. Izzy was on Clary's other side, resting her chin on Clary's shoulder and being basically curled together around the pregnant omega. It was nice that the two had still remained so close, even after their relationship had come apart.

On Isabelle's other side sat her mate Lydia and between them was little Laura nestled. The baby girl was deep asleep, Isabelle running gentle fingers through the dark fuzz of Lightwood-hair, never letting her daughter too much out of sight.

The Lightwoods really were very protective betas in a hovering way when it came to their family. Jace tilted his head up a little to confirm that yup, Alec was standing right behind him, leaning against the couch and drinking what smelt like tea. Magnus was sitting in the armchair opposite them, reading one of his countless magic-books, with Madzie perched on his knee, curiously looking into the book too. Simon sat next to Clary, playing with the omega's hair.

"Magnus, you're really old", stated Simon suddenly and turned toward the warlock.

"...Most conversations that start this way end with my conversation partner turned into a frog."

Jace snickered at the displeased look on Magnus' face and the embarrassed blush on Simon's face. "No, that was not what I meant. Uh, I just... We're still looking for baby names and we just can't agree on _anything_ and I figured, since you're old, you'd know a lot of names? Preferably no names of any of your countless former lovers, please."

Magnus snorted as he looked up at the other alpha. "Simon, I am not sharing my list of good baby names with you and your mate."

"Why not?", asked Clary confused.

Magnus raised one elegant eyebrow and waved into the general direction of Jace and Alec. "Have you seen the pretty beta and the pretty omega I have? Do you know how ridiculously pretty the babies are going to be that those two will produce? All good baby names I have are _ours_."

Jace was pretty sure his heart stopped and he couldn't help but place a hand on his stomach. So that meant that Magnus _wanted_ to have kids? Or, well, wanted Jace and Alec to have kids. Okay. Good. Though when Alec behind him snorted, Jace felt his anxiety level rise again.

"With our luck, Jace will pass on that puppy-pout of his and then you and I will _never_ have anything to say in our home again, Mag", warned Alec with fond amusement.

"I don't think pouting is genetic", laughed Isabelle and rolled her eyes.

"Who knows? I'm convinced Laura has the same smile as you", argued Lydia with a smile.

Isabelle blushed a little as her eyes found their sleeping daughter. "Well, okay, _maybe_."

"But like, would your kids have heterochromia?", asked Simon curiously. "Like, a dark-haired, grumpy, tiny Shadowhunter with a bow and arrow and blue-brown eyes. Hehe."

"...Grumpy?", grunted Alec unimpressed, glaring at Simon before turning to Jace. "But will they?"

"W—What?", asked Jace a bit startled.

"Our hypothetical future children with your puppy-pout and my grumpiness, will they hypothetically also have heterochromia?", elaborated Alec, reaching a hand out to caress Jace's hair.

"...I... I don't know", admitted Jace with a frown. "Since Valentine kind of killed my parents and stole me literally out of the womb, there's no one who could tell me if my heterochromia is genetic, or if it's the side-effect of Valentine's shitty parenting."

"How could your eyes be a side-effect of that?", wanted Clary to know, looking bewildered.

"Heterochromia is mostly caused by injuries to the eye when a baby is still developing", supplied Magnus very gently, looking at Jace with those sorrowful eyes as he always did when he wished he would have been able to protect Jace during his childhood.

"Well, I guess we just have to try and see then, won't we?", inquired Alec playfully to lighten the mood, tracing his thumb along Jace's cheek, making the blonde blush.

"Don't wait too long. I want my baby to grow up with his or her cousin", warned Clary, a hand on top of her stomach and Isabelle next to her laughing in agreement.

Clary's eyes were sparkling and she was grinning teasingly at Jace and the others were laughing and Jace just couldn't keep it in any longer, he stared at his sister with wide eyes. "I'm pregnant."

For another moment, there was still laughter. But when the others noticed that Jace wasn't joining in and that the blonde was still staring with very wide eyes, there was suddenly a _very_ eerie silence.

"Are you... Are you serious?", asked Alec stunned, putting his tea-cup down. "Are you _sure_?"

"I... took seven pregnancy tests. So yeah. Kinda", shrugged Jace and made a face. "I—I don't know how it happened. I mean, I was so sure I got my shots before my last heat, I didn't _mean_ for this to happen, I swear, I just... I must have forgotten, or maybe the shots failed, or-"

"Jace, slow down", requested Magnus very gently, putting Madzie down so he could get to his slowly frantic growing omega. "Take a deep breath and pause for a second, sweetheart."

"I'll be a big sister?", asked Madzie hopefully as she reached Jace before Magnus did.

She tugged on his shirt and stared up at him endearingly and very eagerly. Jace could just stare down at her with his mouth hanging slightly open. Lydia exchanged a concerned look with Alec and after a confirming nod from the beta did Lydia get off the couch.

"Madzie, sweetie, how about we go and get some ice-cream?", suggested Lydia gently.

"Yeah. That sounds like a great plan!", agreed Simon nervously as he took in the atmosphere.

Isabelle and Clary threw Alec matching 'fix whatever the hell this is'-looks. Carefully, Isabelle shouldered Laura as they got off the couch too before they all left the loft together with a slightly protesting Madzie. That left Jace alone with Alec and Magnus.

"Sweetheart, you don't... _have_ to have the child", whispered Magnus very gently and reluctantly.

"W—What?", asked Jace confused and wide-eyed.

"It's your body and... Alec and I, what we were just saying, it was all just in good humor, love."

"Y—You... don't... want the baby...?", whispered Jace heartbroken, hugging his midsection tightly.

"That's not what Magnus said, Jace", sighed Alec as he knelt down in front of Jace, gently grasping the blonde's chin and tilting his head so he had to look at Alec. "You just nearly had a panic attack about being pregnant. So what Magnus means is that... if you're panicking because you don't _want_ to have a baby, then you need to know that Mag and I love you and stand behind you, even... even if you do not want the baby, because it's your body."

Jace hugged his middle in a protective manner. "It's my baby, I'll not kill my own child."

Magnus and Alec shared a relieved sigh, the beta leaning against his warlock for comfort. Though then, after a moment, Alec frowned up at Jace, watching him critically. "Then... why the panic?"

Jace averted his eyes, looking kind of guilty. "I... didn't know if _you_ wanted a baby, or... or if you'd be... angry... I should have gotten my shots, I don't know _why_ I forgot."

"Because you're shouldering too much on your own. Again", sighed Alec as he leaned up to kiss his omega gently. "You try to take Madzie off our hands to make our jobs easier, you spent half your time helping your and Simon out with preparing for their baby, you regularly babysit for Izzy and Lydia, you're _also_ still an active Shadowhunter..."

"We're not _angry_ with you, Jonathan", chided Magnus gently before he stole a kiss of his own from their blonde. "You didn't do it on purpose and even _if_ you did, we'd only be upset that you didn't talk to us before then. We're a mated triad, we need to be able to trust each other with _everything_. And it pains me to think that you must have _known_ you're pregnant before today and that you kept it to yourself, festering your... fears of how we'll regret. We're your mates, we're behind you. And... just because we were joking earlier doesn't mean I wasn't serious. I _want_ children, I can't imagine anything more beautiful than a tiny, adorable combination of the two people I love most."

Jace flushed a little and relaxed visibly. "I... I've known for... a couple of days..."

"Well, we're in this _together_. All four of us", assured Alec seriously, caressing Jace's cheek.

"...Four?", echoed Jace a little confused.

"Well, Madzie seemed eager to become a big sister", chuckled Magnus fondly.

"I think... I think it's time we make her official too", admitted Alec with a slight frown. "She's been staying with us because you're still sorting things out with the warlocks, but... I don't want her to leave to live with some nice warlock couple somewhere else."

Magnus looked very relieved at that before kissing his beta deeply. "I'd... love that. I wasn't so sure if you'd..." Magnus paused and chuckled a little as he shook his head. "I think I'm in no position to chide you, Jace, since I did the same thing about Madzie's adoption..."

"If you're okay with that too, Jace", added Alec as he turned toward their omega. "I mean, with you pregnant now... It's going to be... a bit harder with two kids."

"I don't care how _hard_ it's going to be", grunted Jace with a glare and a growl. "Madzie's _mine_."

All three looked surprised at that. Jace hadn't even realized how much he had bonded with the little warlock since they had taken her in. But it was really hard not to because she had been through so much pain because of Valentine, her and Jace shared their childhood abuse even if Madzie had only been with Valentine for a few weeks. It was enough to make Jace more than just protective of her.

"Well then, it's decided. Our little family is about to grow", smiled Magnus gently.

/2 Months Later\

Magnus somehow enjoyed the slowly growing despair of Simon Lewis. Him and Clary were still trying to figure out the perfect name for their baby girl. And while Clary would be happy to snuggle up together and bounce ideas around, Simon was taking this _way_ too seriously.

"No, with a name like that, she'll be teased. I don't want my daughter to be teased on the school ground", argued Simon with a frown as he paced and waved his arms around wildly.

Isabelle rolled her eyes amused at that and took a bite of the pizza they had ordered in. Madzie was sitting on Alec's lap next to Isabelle. She continuously patted Laura's head as the baby was sitting on Isabelle's lap, giggling every time Madzie would pat her. While doing so, Madzie got her hair braided by a highly concentrated Alec. He always wanted it to be perfect. Jace smiled gently as he watched that. Alec was so adorable with Madzie, he couldn't wait to see the beta fuss over their baby. A blush lit up Jace's face as Magnus wrapped an arm around his middle to rest his hand on Jace's barely bulged stomach, caressing it softly. Sighing, the omega snuggled up against his alpha on whose lap he was sitting. He tilted his head a little in thought.

"What about Dorothea?", suggested Lydia thoughtfully as she watched Madzie and Laura.

"Do...", started Simon with wide eyes, pausing as he turned toward Clary.

The redhead's eyes were sad for a moment before a soft smile found its way onto her lips. "She... was always like a big sister to me. She did so much to protect us during the war. She... died a hero. I... I think I'd like that. Dorothea. It's a good name, right?"

She craned her neck to look up at Simon nearly pleadingly, the vampire softened at that look and nodded in agreement. Dot had died to help them save the world, after all.

"And what about you guys? Did you already figure out a name?", asked Isabelle teasingly.

Alec and Magnus remained quiet at that. Magnus had had a _lot_ of suggestions, he had given Jace an entire list of names, really. Just because he had never been able to have own children didn't mean he never thought or wished or fantasized. Now he had the perfect beta and the perfect omega and they would make the most perfect babies and Magnus couldn't wait. He didn't care what names Jace would pick – and Alec was completely lost and overwhelmed with that decision in general.

"Belinda, if it's a girl, and Balthazar, if it's a boy", replied Jace with the smallest smile.

"Belinda Wayland? Belinda Herondale. Belinda Lightwood. I don't know", mused Simon, frowning.

"Belinda Bane", corrected Jace, earning a surprised look from Magnus. "What? Wayland... is a name Valentine _stole_. Herondale is a name... I have no _real_ ties to. And honestly, Alec and I talked about this. Lightwood... Isabelle and Lydia are continuing the Lightwood name. _We_ want a blank slate, a fresh start for our family. And since our children will have Alec's and my DNA, we want them to have your last name, Magnus, to show that they're yours too."

Magnus was so touched, he couldn't quite breath for a moment before he leaned in and kissed Jace gently. Alec watched them with a soft smile, resting his chin on top of Madzie's head. After all, they had adopted Madzie as a Bane too, considering Magnus was the High Warlock it just made more sense to give their warlock daughter his name instead of a Shadowhunter's name. And their children should all have the same last name. Jace had approached Alec about this a week ago or so.

/2 Months Later\

Jace had narrowed it down to either Balthazar or Belinda – granted, all names on Magnus' favorite name list were a little weird or old-fashioned, but then again, they also kind of fit. Sounded sophisticated and stuff like that. He liked those two best and he had told Alec, who was pretty much fine with everything, though he had requested that if they have a daughter he would like for her to get the middle name Isabelle, something that Jace whole-heartedly agreed to.

"I swear, if he looks at you the wrong way or says a single wrong word, I will _break_ him."

Jace blinked and smiled a little as he turned toward his angrily glaring parabatai. Magnus sighed bemused, grasping Jace's hand to link their fingers while looking over at the glowering archer. It wasn't an exaggeration to say that Alec hated Victor Aldertree. Alec would _never_ forget how Aldertree had taken the reigns from the Lightwoods, had opened the hunt on Jace, had imprisoned Jace in the City of Bones, had gotten Isabelle addicted to vampire venom – which had torn the growing relationship between Simon, Clary and Isabelle apart back then because she started to use Simon for the purpose of getting high, which had endangered her, nearly made Simon addicted to human blood and had nearly cost her Clary's trust for good. And everyone knew Aldertree had never liked Jace to begin with. He had disliked Jace for being Valentine's son, for being mated to his parabatai and breaking the rules, for being mated to a warlock. It had really been a matter of endurance while Aldertree was head of the Institute and everyone was very glad that position was returned to the Lightwoods by now. Alas, Aldertree remained as the head of the infirmary. Which was exactly where the mated threesome was headed right now, because they had an appointment for an ultrasound to determine whether they were having a boy or a girl. Not that it _really_ mattered. They'd love their baby regardless, but it just made things feel so much more real to have the knowledge and to imagine things more clearer. Jace leaned against Alec and kissed him gently.

"Jace", stated Victor Aldertree little impressed as he took them in. "Please lay down."

Jace nodded sharply and did so, allowing the unpleasant beta to apply gel to his stomach and use the ultrasound machine. Magnus and Alec were standing on either side of Jace in a very protective manner. Magnus was an insanely strong alpha and he was not above displaying it right now, because he knew how Aldertree made both Jace and Alec feel and the last thing Magnus wanted was for Jace to be upset, not while he was in this state. Well, not _ever_ , actually.

"How's the baby?", asked Alec with an edge to his voice.

"The baby is... well developed", replied Aldertree. "Would you like to know the sex?"

"Yes", chorused all three of them.

Jace reached out and took both his lovers' hands to squeeze them tightly, oddly nervous. "It's a girl."

Jace's heart skipped a beat. A daughter. They were going to have a daughter. Technically, they already had a daughter, they had Madzie – who was currently staying at Luke's and enjoying her borrowed grandpa. So Jace guessed they kind of knew how to deal with a girl? Maybe?

"We're going to have a daughter", whispered Jace softly beneath his breath.

Alec was squeezing his hand so tightly, Jace was pretty sure it should break any second now, while Magnus was peppering Jace's knuckles with kisses, the warlock radiating.

"Congratulations", grunted Aldertree, despite himself offering a nearly genuine smile.

/2 Months Later\

Alec frowned confused as he looked around the apartment. Jace should be home. Alec had been out with Madzie to get her a couple new clothes together with Izzy, who never missed out on an opportunity to buy new clothes for Laura either. And it was kind of nice, to just be out with only his sister. Still, he had been looking forward to coming home and being greeted by his pregnant omega.

"Jace? You home, love?", called Alec out loudly, sniffing the air to find the scent of his omega, just to pause because he also picked up Magnus' scent. "...You're both home? Where are you?"

"Bedroom", replied Magnus, sounding concerned.

Alec did not like that sound, especially not now that their omega was pregnant. Part of Alec was so incredibly on edge about Jace being pregnant. They had all lost so much and endured so much during the war and somehow, Jace's biggest fear – that those he loved would be destroyed – had bled into Alec's sub-conscience. So now Alec was anxious and afraid that somehow fate would take the baby from them before it was even born, even though the rational part of Alec's mind told him that this was stupid and that not _everyone_ Jace loved was taken from him – Alec, Magnus, Isabelle, Clary, Simon, Madzie, Max, Maia, Bat, they were all around and planned on staying around.

"Mag? What's wrong?", asked Alec gently as he saw Magnus crouching in front of the closet.

He approached the warlock and once he was next to Magnus, he saw what had the alpha concerned. There, in their closet, was Jace. That in itself wasn't too rare, because Jace generally built his nest in the closet when his heat was coming up. The closet was spacious and he just had to rearrange their clothes down onto the ground where Jace, Magnus and Alec could easily fit together. Never would Alec have thought that Magnus' obsession with fashion would actually come in handy for their matebond, but the fact that Magnus had so many clothes and thus a spacious walk-in closet gave Jace a safe space for his nest. But normally omegas only nested shortly before their heat and shortly before the birth. Due to the pregnancy, Jace could not go into heat and he was definitely too early for birth. Alec gulped anxiously as he snuggled up to Magnus, the warlock wrapping an arm around Alec to comfort the beta. Jace looked miserable as he was curled together in the center of the nest.

"What if I'll be a failure?", asked Jace, the scent of anxious omega filling the whole room. "I mean, look at who raised me! Valentine himself. What do _I_ know about parenting? And babies? I know nothing about babies. And Maryse and Robert were kind of not the _best_ examples of good parenting either, now were they, Alec? Didn't really teach about avoiding favoritism with the kids! What... What if I'll end up picking a favorite and then my biological daughter will grow up to resent me like Izzy resents Maryse because I picked Madzie over her and I'll be a horrible parent?"

"Yeah, that's been going on for the last half hour now", sighed Magnus, nuzzling Alec desperately. "I've already tried _everything_. He didn't let me come into the nest either. He's so busy driving himself into a frenzy, he won't accept comfort. Fix this, Alexander, you're my Jace-whisperer."

Alec would have smiled at that, if the situation wasn't actually serious, because this was the first time Jace was freaking out about this pregnancy on the account of him not being good enough for this baby. He had freaked out how Maryse and Robert would take it, he had freaked out about the general idea of being pregnant, he had freaked out about Alec's and Magnus' reaction as soon as he had found out about the pregnancy, after all. But this? Dealing with Jace's insecurities about not living up to expectations and not being good enough, that was something Magnus and Alec have been working on ever since they had become a mated threesome and it was so hard.

"Jace...", started Alec, unsure what to say to reassure his omega.

"Don't be sad, momma", whispered Madzie softly as she let go of Alec's hand to crawl into the nest and in between Jace's arms to snuggle up to the omega. "You're gonna be fine and I'll help and be a really-really good big sister for my little sister. Don't worry."

Jace stared at her wide-eyed and so did Magnus and Alec. Alec was stiffly leaning against Magnus, blinking slowly. They had officially adopted Madzie finally, but she had never called them dads or Jace mom before. The omega started purring soothingly, the scent of anxiety dissolving as he curled tightly around his adopted daughter, hugging her close.

"Thank you, buttercup, I know you'll be a great big sister", whispered Jace gently.

"So... are we allowed in too now?", asked Magnus, itching to comfort his omega.

Jace scooted over a little, allowing space for Magnus to lay behind him, while Alec went to lay on Madzie's other side, kissing her cheek. She giggled as she snuggled up to both Jace and Alec. Magnus growled pleased as he wrapped his arms around Jace's waist and buried his nose in the blonde hair, inhaling the extremely soothing scent of his pregnant omega. His hands clasped together around Jace's round stomach, caressing it tenderly.

"You okay now, Jace?", asked Alec softly, looking quizzically at his parabatai.

"Yeah", nodded Jace, small smile in place. "If I'm doing good enough that Madzie accepts me, then... I don't think I'll screw up too badly with the baby, right?"

"You're a wonderful mother and you'll be perfect for our baby too", assured Magnus.

/2 Months Later\

Magnus was pacing nervously. He had been pacing for the past hour now. At first, Alec still had cared to try and sooth his alpha, but by now he was growing more frantic himself. The only things grounding Alec were Madzie perched on his lap and Isabelle holding his hand.

"Magnus", tried Clary gently, reaching out for the warlock. "Sit down, please. Jace will be alright."

"Of course will my sweetheart be alright. And so will the little cupcake brewing inside of him, but please let me pace in peace until I get to hold my precious little princess of a daughter."

Clary looked only mildly amused, though she let the alpha continue pacing until they were allowed inside. They had started out inside – at least Magnus and Alec had – but those two _really_ couldn't behave themselves while Jace was in pain so the doctors had been forced to remove the alpha and the beta from the room. Everyone present was relieved when they were allowed back inside by a smiling nurse. Smiling was good. Clary heaved a relieved sigh, grasping Isabelle's hand to link fingers with the beta. Simon had an arm wrapped around Clary's shoulders. Lydia on Alec's other side smiled and rested a reassuring hand on his best friend's shoulder, squeezing. The other two couples had left their children in the care of Luke when Jace had gone into labor.

"I can't wait to meet Dorothea's future best friend", whispered Clary eagerly.

"Excuse me? This girl is going to be Laura's future best friend", argued Isabelle half-seriously.

"Stop planning our daughters' future", grunted Alec and rolled his eyes as he stormed into the room.

"Hey, sweetheart, how do you feel, my love?", asked Magnus nearly frantically.

He basically collapsed on the bed where a completely exhausted Jace was laying, gently cradling Jace's face in his hands and peppering it with kisses. At least until he heard a cry. The warlock froze and so did the others. Everyone turned toward the smiling nurse who was handing the baby over to Alec. Alec was staring at the pink bundle with wide eyes, as though he was afraid he'd drop it.

"I—I... What do I _do_?", asked Alec nearly panicky.

"For one, don't drop our daughter", grunted Jace, voice a little tired. "Come here, helpless idiot."

Alec gladly obeyed and sat down next to Magnus on the bed, looking desperately up at his mates. Clary, Lydia, Isabelle and Simon lined up on the other side of the bed, with Clary gently kissing Jace's forehead. Magnus was staring at the baby in utter awe. When Alec kept looking kind of afraid of dropping the baby, Magnus decided to take the little one from his beta.

"Hello, my precious little princess. I'm your ayah, this startled deer in the headlights right here is your papa and that gorgeous, exhausted angel is your mommy", whispered Magnus gently. "Madzie, come here. Meet your new baby sister Belinda. Belinda, this is your older sister Madzie."

Madzie stared doe-eyed as she tried to climb onto the bed. Alec reached out for her and lifted her up onto his lap so she could see both Jace and the baby. Jace smiled at her in a reassuring manner.

"Hello", grinned Madzie happily, reaching out for the baby's tiny hand. "I'm your new sister."

For a while, everyone was just staring at Belinda and cooing over her. After a couple moments did Alec step back some to lean against the wall. Belinda was cradled against Jace's chest, with Madzie laying on Jace's other side, watching the baby in awe. Magnus was cooing sweet nonsense while Jace was slowly drifting off to sleep. As amazed as Alec was by it all, he was also quite overwhelmed so he took a step back and took in the view of his family curled together on the bed.

"Hey there big brother, you alright?", asked Isabelle gently as she stepped up to him.

"Y—Yeah, I just...", drawled Alec dazed, still staring at them. "We... Jace and I made a _human_. We made this perfect, beautiful little human. But... what do we do _now_?"

"You... take care of the perfect, beautiful little human", supplied Isabelle, soft smile on her face as she nudged her older brother. "You're taking good care of Madzie. You took great care of me and Maxie and Jace. You will be a great dad, Alec. Don't panic now."

"Trying", grunted Alec with a sharp nod. "It's just... a lot..."

"Alexander?", asked Magnus curiously. "Why don't you join us? We have a baby to coo over."

Alec chuckled fondly as he approached his mates again and squeezed in with his family.

/2 Years Later\

Alec did not _do_ babysitting. It was really not his thing. But Isabelle had been standing in front of the door with a charming smile and two toddlers, thrusting them into Alec's arms and declaring that she and her mate _needed_ a night to themselves and that Alec ought to fulfill his duty as best uncle because Luke had turned tail at the prospect of spending yet another weekend as babysitter – sure, Luke loved being a grandpa, but all those little Shadowhunters were exhausting and the poor man really needed a break from babysitting too. So did Alec, two hours into babysitting. Especially since, somehow, Clary had heard about Alec 'volunteering' as a babysitter and had eagerly dropped Dorothea off with him, claiming that her son was already at Bat and Maia's and if Alec was to take care of Dorothea, then Clary and Simon would actually get a day off from parenting and hey, while Alec was already watching the other two little ones, he totally could, right? He kind of couldn't. Which was to equal parts ridiculous and embarrassing, considering he was a two times dad himself.

"Henry, no, you can't eat that", sighed Alec and took the magic book from the little boy.

Henry – Henry Alexander Lightwood, much to Alec's pride – turned his large, hazel-brown eyes on Alec, staring at his uncle in confusion. He was so adorable, with Lydia's sandy-blonde hair and the Lightwood eyes, the same gentle brown eyes as Alec and Izzy. It was what made being irritated by the toddler so hard for Alec, because Henry reminded him a lot of Izzy.

"No eating books", chided Henry's big sister seriously.

Well, as seriously as a two-year-old toddler could be. Alec smiled amused. Laura was wonderful. She _adored_ Alec, Alec was her favorite uncle and just like Alec and Lydia, Laura was very strictly following all the rules. Honestly, Isabelle had made two amazing kids there.

"Clever girl", praised Alec with a smile as he ruffled her curls before pausing. "Wait. Where are the others...? Where are Belle, Madzie and Doro...?"

Dorothea and Belinda were inseparable and Clary and Jace were kind of already planning their parabatai ceremony in their heads. Both of them missing was _never_ a good sign, because just like their mommies, those two ran head-first into any danger they could find.

"Did you lose our daughters again, Alexander?", chided Magnus playfully as he entered the loft.

Alec made a face as Magnus and Jace entered the living room. Magnus had accompanied Jace to the doctor's, because both Isabelle and Clary had pregnant at the same time and their second-born – barely a month old right now – had been born around the same time. It had made Jace eager and even though he was a little late to the party, the threesome sat together to actually talk baby plans this time. Jace was already rather far along too, so there would barely be a few months between the youngest of the next generation. Alec flushed as he took in how gorgeous his highly pregnant omega looked, all round and glowing. He also flushed in mild embarrassment at being caught.

"How's the baby?", asked Alec tensely for a second.

"Our son is healthy and perfect", assured Magnus gently before sitting down next to the beta.

"Where are our daughters though?", inquired Jace with a frown. "You did lose them, didn't you?"

"I didn't _lose_ them. They're somewhere in the apartment", grunted Alec. "...I hope."

Jace rolled his eyes a bit pointedly as he rested one hand on his belly and he inhaled deeply. "Belinda Isabelle Bane, I told you no playing hide and seek with papa _without_ telling papa!" Jace paused for a second, looking around the room with a frown. "Madison Bane, if you portaled your sister away again, you are going to be grounded for a _month_."

It took their two daughters and Dorothea two seconds flat to rush out of Belinda's bedroom and stand obediently in front of the adults. Magnus smiled bemused. Jace had this whole omega-of-the-house authority thing down to an art form, really. Not just with their daughters, but also with his mates. Madzie grinned sheepishly, her wild, frizzy curls pointing into every possible direction. Belinda all the while stared up at Alec with her impossibly large hazel eyes, those undeniable Lightwood-eyes, her broad blonde curls put up into two pigtails. Alec instantly melted into a puddle of parental goo, which Magnus related to, because he couldn't deny their daughters anything either. Not only did she have those wide Lightwood-eyes, no, she also had Jace's puppy-pout. Jace chuckled knowingly. Dorothea all the while was pouting up at Jace – she truly was the splitting image of her mother Clary, with the bright fire-red hair and light brown eyes.

"One day, you kids are going to drive Alec insane", chuckled Jace, resting one hand on Dorothea's head and one hand on Belinda's head. "You need to listen to him more often."

"Uhu!", agreed Laura seriously, long black curls falling into her turquoise eyes as she nodded wildly. "Uncle Alec's always right! You need to listen!"

Alec grinned pleased, happy that at least _one_ of the kids was on his side. Dorothea and Belinda all the while were still pretending to be innocence incarnated, much to Magnus' amusement.

"You're a hell of a lot of trouble, Bells", sighed Jace as he knelt down in front of his daughter.

"That's why I call her Hell's Bells, mom", giggled Madzie as she sat down with Alec.

"Mommy", squeaked Belinda and jumped Jace in a tight hug. "Missed you!"

Magnus joined Madzie and Alec on the ground, Alec having Henry in his lap. The littlest Lightwood babbled happily. Dorothea also sat down on the floor now, back facing Alec and silently demanding for Alec to braid her hair. He did make the coolest braids; all the girls knew that and all the girls thus came to Alec to get their hair done. Smiling amused, Alec reached out for the fire-red curls to braid Dorothea's hair for her, causing Laura and Belinda to look slightly jealous.

Magnus smiled gently as he looked his family over, warmth filling his heart when Jace and Belinda sat down with them too, Belinda cuddled up very closely to her mommy – as she always did when she did something to upset Jace, because she knew Jace couldn't stay mad at her whenever she was very bright and affectionate. Magnus wrapped one arm around his omega, pulling Jace against his side so he could kiss Jace's cheek gently. The blonde hummed contently as he rested his cheek against his alpha's shoulder while watching Alec fondly. Their little family was absolutely perfect, was what Jace thought when resting a hand on his rounded stomach.

"I'm glad I get a brother this time", hummed Madzie while tickling Henry's stomach. "Boys are funny. Laura gets to have a little brother too and she says it's great."

"Uhu", confirmed Laura brightly. "I'll teach him all the things."

"All the things, yeah?", asked Alec fondly.

Laura nodded in determination, making the adults smile fondly. Dorothea all the while wiggled her nose at that and shook her head in utter determination, amusing the three adults even more.

"Is not that great", hummed Dorothea. "Little brothers are silly."

Jace sighed softly, eyes gentle as he looked at his family. He really hoped that Belinda and Madzie would take to their little brother and not think him silly. Deep down, he knew it would be alright.

 _~*~ The End ~*~_

* * *

 _Author's note: I want to keep "The A and O of Family" series going for a while, but I've... grown insanely fond of Lyzzy as a couple. So on the long run of working on this series, I will be happier writing Climon and Lyzzy instead of the threesome, which is why I rewrote this shot. I'll keep the alternate version up too - see it as an AU, if you want to - but this right here is the new canon for my headcanon. In the planned sequel to "The A and O of Love", I'll then inevitably break Simon/Isabelle/Clary up and make Lyzzy happen.  
_


	2. Alternate SimonClaryIzzy Version

Malace || Shadowhunters || Malace || Hell's Bells || Malace || Shadowhunters || Malace

Title: Hell's Bells – How to Care for Your Pregnant Omega

Fandom: Shadowhunters: The Mortal Instruments

Disclaimer: All rights to the Shadowhunters reserved to Ed Decter, the books the Shadowhunters is based off and its characters belong to Cassandra Clare. This fanfiction on the other hand is entirely mine. No money is made with this, though reviews are more than welcomed.

Warnings: shounen-ai, polyamory (threesome), ABO-verse, mpreg, pregnancy, fluff, family fluff, hurt/comfort, adoption, shoujo-ai, hetero

Main Pairing: Magnus/Alec/Jace

Side Pairing: Simon/Isabelle/Clary

Shadowhunters Characters: Jonathan Christopher 'Jace' Wayland, Magnus Bane, Alexander Gideon 'Alec' Lightwood, Isabelle Sophia 'Izzy' Lightwood, Clarissa Adele 'Clary' Fray, Simon Lewis, Madzie, Victor Aldertree

Own Characters: Belinda Isabelle Bane, Dorothea Elaine Lewis, Lucian Alexander Lewis

Summary: Jace has been feeling like shit, until he realizes that he's pregnant. With all the stress, ironically because Clary is pregnant and he is being a good uncle-to-be, he completely forgot to get his shots before his last heat and now he's pregnant. He doesn't even know if Alec and Magnus want to have children. What if they don't? Will Magnus and Alec catch on and comfort their omega?

 **Hell's Bells**

 _How to Care for Your Pregnant Omega_

Jace's heart was beating too fast. It was hammering against his ribs like it wanted to break out. He couldn't believe it. Then again, the last six pregnancy tests he had taken all showed the same thing.

Jace was pregnant with Alec's baby.

He knew it could only be Alec's, because Magnus was a warlock and warlocks were sterile. Which was kind of why the threesome had never brought up the matter of children before. Granted, when the three of them had gotten together, they had still been in the middle of the war against Valentine and that was just really not the right kind of time or environment to have a baby, or to be pregnant. Jace _needed_ to be there when they caught Valentine and ended his madness, he would not have been able to live with himself if he had been forced to sit it out because he was pregnant.

But he had also never planned for it to be like this. Well, no one ever planned for an unplanned pregnancy, hence the name, huh? Jace glared viciously at the pregnancy test and threw it to its kin.

He had been feeling like shit for the past two weeks. Nauseous and throwing up a lot, moody and with weird aches. He tried to deny it at first, because it couldn't possibly be. But then, then he started to wonder. Had he _really_ gotten his contraceptive shots before his last heat? Had he really? Or had he maybe forgotten about it? Perhaps he had. He had been kind of busy with everything lately. Sure, Valentine was taken care of, but now they had to clean up after Valentine. And then Madzie had kind of been living with them and since Magnus was so busy as the High Warlock – because Madzie was not the only orphan and abandoned warlock left in the wake of Valentine's attempted genocide – and Alec was now acting head of the Institute, which meant that it kind of fell to Jace to take care of Madzie most of the time. Which kind of figured, considering he was an omega and omegas took care of the children. Oh. What... if now that he actually _was_ pregnant, his mates would want him to stay at home? Jace frowned displeased and shook his head.

No. No, Magnus was a good alpha and he would not force Jace to be a stay-at-home omega. Those were just the stupid hormones talking. Magnus had never been bothered that Jace, as an omega, was out in the field and putting himself into danger, even though _many_ magical communities still thought that omegas should not be put at risk like that; Shadowhunters included. And Alec was the perfect beta, he knew exactly how to balance Magnus and Jace out and he would totally intervene even on the non-existent event that Magnus would be _that_ old-fashioned.

Anyway. Back on topic. Jace was pregnant with Alec's child and he had no idea how it had happened. Well. He knew _how_ , considering that his heats shared with his beta and his alpha were _more_ than just memorable. But how exactly had he forgotten to get his shots? Was it because he was overwhelmed with Madzie? And if he was already overwhelmed with her, how in the world was he supposed to handle a _baby_? Or had it been because of Clary? Lately, he had been spending a lot of his time with Clary, because she was pregnant. And the pregnant female omega was being very clinging with her 'brother' since then, omega-bonding and seeking comfort from her self-chosen family. Even after Valentine's lies had been exposed, Clary didn't care – she had started seeing Jace as her brother and she was not about to stop just because their shared blood had been a lie. Jace found himself clinging onto that love, that piece of family. Which was why he was so willing to accompany her everywhere, go baby-toys and baby-furniture and baby-clothes shopping with her. He helped Simon, who was _utterly_ helpless, baby-proving the apartment and putting together the furniture. And all of that on top of taking care of Madzie and still being an active Shadowhunter. He was kind of stretched thin, even if he wasn't the High Warlock of Brooklyn or the head of the Institute. So maybe, perhaps, he had kind of forgotten the shots. Had canceled the appointment because something else had come up and he had forgotten to reschedule it?

Or had he subconsciously... just not gotten them? Had his sub-conscience chosen not to reschedule the appointment, because seeing Clary glow like that, seeing Clary be doted on by her very own gentle, loving Lightwood beta, seeing Clary curl up against her own alpha, seeing how proud and strong Simon could be now for his pregnant omega... Jace would be lying if he'd say that he didn't kind of crave that too. Now that the war was over, now that he actually had two mates who loved him and who he loved, he had a... family. He had an actual family and he wanted _more_ of it. He couldn't wait to be 'uncle Jace' and if he was being very honest, he couldn't wait to be... mommy.

So maybe he had forgotten it kind of on purpose without meaning to? If that made sense?

Jace's eyes widened as panic set in once more. What if Alec and Magnus thought he had done it fully on purpose? What if they didn't _want_ a baby? At all? Or just not right now?

He couldn't deal with all of this. It was just too much.

/2 Weeks Later\

Jace was curled together in the corner of the couch, next to Clary. She was already showing, a hand resting on her bulging stomach. Izzy was on Clary's other side, resting her chin on Clary's shoulder and being basically curled together around the pregnant omega. It was adorable. The Lightwood-siblings really were very protective betas in a hovering way when it came to their omegas. Jace tilted his head up a little to confirm that yup, Alec was standing right behind him, leaning against the couch and drinking what smelt like tea. Magnus was sitting in the armchair opposite them, reading one of his countless magic-books, with Madzie perched on his knee, curiously looking into the book too. Simon sat next to Isabelle, playing with the beta's hair.

"Magnus, you're really old", stated Simon suddenly and turned toward the warlock.

"...Most conversations that start this way end with my conversation partner turned into a frog."

Jace snickered at the displeased look on Magnus' face and the embarrassed blush on Simon's face. "No, that was not what I meant. Uh, I just... We're still looking for baby names and we just can't agree on _anything_ and I figured, since you're old, you'd know a lot of names? Preferably no names of any of your countless former lovers, please."

Magnus snorted as he looked up at the other alpha. "Simon, I am not sharing my list of good baby names with you and your mates."

"Why not?", asked Clary confused.

Magnus raised one elegant eyebrow and waved into the general direction of Jace and Alec. "Have you seen the pretty beta and the pretty omega I have? Do you know how ridiculously pretty the babies are going to be that those two will produce? All good baby names I have are _ours_."

Jace was pretty sure his heart stopped and he couldn't help but place a hand on his stomach. So that meant that Magnus _wanted_ to have kids? Or, well, wanted Jace and Alec to have kids. Okay. Good. Though when Alec behind him snorted, Jace felt his anxiety level rise again.

"With our luck, Jace will pass on that puppy-pout of his and then you and I will _never_ have anything to say in our home again, Mag", warned Alec with fond amusement.

"I don't think pouting is genetic", laughed Isabelle and rolled her eyes.

"But like, would your kids have heterochromia?", asked Simon curiously. "Like, a dark-haired, grumpy, tiny Shadowhunter with a bow and arrow and blue-brown eyes. Hehe."

"...Grumpy?", grunted Alec unimpressed, glaring at Simon before turning to Jace. "But will they?"

"W—What?", asked Jace a bit startled.

"Our hypothetical future children with your puppy-pout and my grumpiness, will they hypothetically also have heterochromia?", elaborated Alec, reaching a hand out to caress Jace's hair.

"...I... I don't know", admitted Jace with a frown. "Since Valentine kind of killed my parents and stole me literally out of the womb, there's no one who could tell me if my heterochromia is genetic, or if it's the side-effect of Valentine's shitty parenting."

"How could your eyes be a side-effect of that?", wanted Clary to know, looking bewildered.

"Heterochromia is mostly caused by injuries to the eye when a baby is still developing", supplied Magnus very gently, looking at Jace with those sorrowful eyes as he always did when he wished he would have been able to protect Jace during his childhood.

"Well, I guess we just have to try and see then, won't we?", inquired Alec playfully to lighten the mood, tracing his thumb along Jace's cheek, making the blonde blush.

"Don't wait too long. I want my baby to grow up with his or her cousin", warned Clary.

Her eyes were sparkling and she was grinning teasingly at Jace and the others were laughing and Jace just couldn't keep it in any longer, he stared at his sister with wide eyes. "I'm pregnant."

For another moment, there was still laughter. But when the others noticed that Jace wasn't joining in and that the blonde was still staring with very wide eyes, there was suddenly a _very_ eerie silence.

"Are you... Are you serious?", asked Alec stunned, putting his tea-cup down. "Are you _sure_?"

"I... took seven pregnancy tests. So yeah. Kinda", shrugged Jace and made a face. "I—I don't know how it happened. I mean, I was so sure I got my shots before my last heat, I didn't _mean_ for this to happen, I swear, I just... I must have forgotten, or maybe the shots failed, or-"

"Jace, slow down", requested Magnus very gently, putting Madzie down so he could get to his slowly frantic growing omega. "Take a deep breath and pause for a second, sweetheart."

"I'll be a big sister?", asked Madzie hopefully as she reached Jace before Magnus did.

She tugged on his shirt and stared up at him endearingly and very eagerly. Jace could just stare down at her with his mouth hanging slightly open. Clary exchanged a concerned look with Alec and after a confirming nod from the beta did Clary get off the couch.

"Madzie, sweetie, how about we go and get some ice-cream?", suggested Clary gently.

"Yeah. That sounds like a great plan!", agreed Simon nervously as he took in the atmosphere.

Isabelle threw Alec a last 'fix whatever the hell this is'-look before the threesome left the loft together with a slightly protesting Madzie. That left Jace alone with Alec and Magnus.

"Sweetheart, you don't... _have_ to have the child", whispered Magnus very gently and reluctantly.

"W—What?", asked Jace confused and wide-eyed.

"It's your body and... Alec and I, what we were just saying, it was all just in good humor, love."

"Y—You... don't... want the baby...?", whispered Jace heartbroken, hugging his midsection tightly.

"That's not what Magnus said, Jace", sighed Alec as he knelt down in front of Jace, gently grasping the blonde's chin and tilting his head so he had to look at Alec. "You just nearly had a panic attack about being pregnant. So what Magnus means is that... if you're panicking because you don't _want_ to have a baby, then you need to know that Mag and I love you and are behind you, even... even if you do not want the baby, because it's your body."

Jace hugged his middle in a protective manner. "It's my baby, I'll not kill my own child."

Magnus and Alec shared a relieved sigh, the beta leaning against his warlock for comfort. Though then, after a moment, Alec frowned up at Jace, watching him critically. "Then... why the panic?"

Jace averted his eyes, looking kind of guilty. "I... didn't know if _you_ wanted a baby, or... or if you'd be... angry... I should have gotten my shots, I don't know _why_ I forgot."

"Because you're shouldering too much on your own. Again", sighed Alec as he leaned up to kiss his omega gently. "You try to take Madzie off our hands to make our jobs easier, you spent half your time helping our sisters and Simon out with preparing for their baby, you're _also_ a Shadowhunter..."

"We're not _angry_ with you, Jonathan", chided Magnus gently before he stole a kiss of his own from their blonde. "You didn't do it on purpose and even _if_ you did, we'd only be upset that you didn't talk to us before then. We're a mated triad, we need to be able to trust each other with _everything_. And it pains me to think that you must have _known_ you're pregnant before today and that you kept it to yourself, festering your... fears of how we'll regret. We're your mates, we're behind you. And... just because we were joking earlier doesn't mean I wasn't serious. I _want_ children, I can't imagine anything more beautiful than a tiny, adorable combination of the two people I love most."

Jace flushed a little and relaxed visibly. "I... I've known for... a couple of days..."

"Well, we're in this _together_. All four of us", assured Alec seriously, caressing Jace's cheek.

"...Four?", echoed Jace a little confused.

"Well, Madzie seemed eager to become a big sister", chuckled Magnus fondly.

"I think... I think it's time we make her official too", admitted Alec with a slight frown. "She's been staying with us because you're still sorting things out with the warlocks, but... I don't want her to leave to live with some nice warlock couple somewhere else."

Magnus looked very relieved at that before kissing his beta deeply. "I'd... love that. I wasn't so sure if you'd..." Magnus paused and chuckled a little as he shook his head. "I think I'm in no position to chide you, Jace, since I did the same thing about Madzie's adoption..."

"If you're okay with that too, Jace", added Alec as he turned toward their omega. "I mean, with you pregnant now... It's going to be... a bit harder with two kids."

"I don't care how _hard_ it's going to be", grunted Jace with a glare and a growl. "Madzie's _mine_."

All three looked surprised at that. Jace hadn't even realized how much he had bonded with the little warlock since they had taken her in. But it was really hard not to because she had been through so much pain because of Valentine, her and Jace shared their childhood abuse even if Madzie had only been with Valentine for a few weeks. It was enough to make Jace more than just protective of her.

"Well then, it's decided. Our little family is about to grow", smiled Magnus gently.

/2 Months Later\

Magnus somehow enjoyed the slowly growing despair of Simon Lewis. Him, Isabelle and Clary were still trying to figure out the perfect name for their baby girl. And while Isabelle and Clary were happy to snuggle up together and bounce ideas around, Simon was taking this _way_ too seriously.

"No, with a name like that, she'll be teased. I don't want my daughter to be teased on the school ground", argued Simon with a frown as he paced and waved his arms around wildly.

Isabelle rolled her eyes at that and took a bite of the pizza they had ordered in. Madzie was sitting on Alec's lap next to Isabelle, getting her hair braided by Alec. He always wanted it to be perfect. Jace smiled gently as he watched that. Alec was so adorable with Madzie, he couldn't wait to see the beta fuss over their baby. A blush lit up Jace's face as Magnus wrapped an arm around his middle to rest his hand on Jace's barely bulged stomach, caressing it softly. Sighing, the omega snuggled up against his alpha on whose lap he was sitting. He tilted his head a little in thought.

"What about Dorothea?", suggested Jace softly.

"Do...", started Simon with wide eyes, pausing as he turned toward Clary.

The redhead's eyes were sad for a moment before a soft smile found its way onto her lips. "She... was always like a big sister to me. She did so much to protect us during the war. She... died a hero. I... I think I'd like that. Dorothea. It's a good name, right?"

She craned her neck to look up at Isabelle and Simon nearly pleadingly and both beta and alpha softened at that look and nodded in agreement. Dot had died to help them save the world, after all.

"And what about you guys? Did you already figure a name out?", asked Isabelle teasingly.

Alec and Magnus remained quiet at that. Magnus had had a _lot_ of suggestions, he had given Jace an entire list of names, really. Just because he had never been able to have own children didn't mean he never thought or wished or fantasized. Now he had the perfect beta and the perfect omega and they would make the most perfect babies and Magnus couldn't wait. He didn't care what names Jace would pick – and Alec was completely lost and overwhelmed with that decision in general.

"Belinda, if it's a girl, and Balthazar, if it's a boy", replied Jace with the smallest smile.

"Belinda Wayland. Belinda Herondale? Belinda Lightwood. I don't know", mused Simon, frowning.

"Belinda Bane", corrected Jace, earning a surprised look from Magnus. "What? Wayland... is a name Valentine _stole_. Herondale is a name... I have no ties to anymore. And honestly, Alec and I talked about this. Lightwood... Alec and Izzy lived so long under the pressure of that name. We want a blank slate, a fresh start for our family. And since our children will have Alec's and my DNA, we want them to have your last name, Magnus, to show that they're yours too."

Magnus was so touched, he couldn't quite breath for a moment before he leaned in and kissed Jace gently. Alec watched them with a soft smile, resting his chin on top of Madzie's head. After all, they had adopted Madzie as a Bane too, considering Magnus was the High Warlock it just made more sense to give their warlock daughter his name instead of a Shadowhunter's name. And their children should all have the same last name. Jace had approached Alec about this a week ago or so.

/2 Months Later\

Jace had narrowed it down to either Balthazar or Belinda – granted, all names on Magnus' favorite name list were a little weird or old-fashioned, but then again, they also kind of fit. Sounded sophisticated and stuff like that. He liked those two best and he had told Alec, who was pretty much fine with everything, though he had requested that if they have a daughter he would like for her to get the middle name Isabelle, something that Jace whole-heartedly agreed to.

"I swear, if he looks at you the wrong way or says a single wrong word, I will _break_ him."

Jace blinked and smiled a little as he turned toward his angrily glaring parabatai. Magnus sighed bemused, grasping Jace's hand to link their fingers while looking over at the glowering archer. It wasn't an exaggeration to say that Alec hated Victor Aldertree. Alec would _never_ forget how Aldertree had taken the reigns from the Lightwoods, had opened the hunt on Jace, had imprisoned Jace in the City of Bones, had gotten Isabelle addicted to vampire venom – which had _nearly_ torn the growing relationship between Simon, Clary and Isabelle apart back then because she started to use Simon for the purpose of getting high, which had endangered her, nearly made Simon addicted to human blood and had nearly cost her Clary's trust. And everyone knew Aldertree had never liked Jace to begin with. He had disliked Jace for being Valentine's son, for being mated to his parabatai and breaking the rules, for being mated to a warlock. It had really been a matter of endurance while Aldertree was head of the Institute and everyone was very glad that position was returned to the Lightwoods by now. Alas, Aldertree remained as the head of the infirmary. Which was exactly where the mated threesome was headed right now, because they had an appointment for an ultrasound to determine whether they were having a boy or a girl. Not that it _really_ mattered. They'd love their baby regardless, but it just made things feel so much more real to have the knowledge and to imagine things more clearer. Jace leaned against Alec and kissed him gently.

"Jace", stated Victor Aldertree little impressed as he took them in. "Please lay down."

Jace nodded sharply and did so, allowing the unpleasant beta to apply gel to his stomach and use the ultrasound machine. Magnus and Alec were standing on either side of Jace in a very protective manner. Magnus was an insanely strong alpha and he was not above displaying it right now, because he knew how Aldertree made both Jace and Alec feel and the last thing Magnus wanted was for Jace to be upset, not while he was in this state. Well, not _ever_ , actually.

"How's the baby?", asked Alec with an edge to his voice.

"The baby is... well developed", replied Aldertree. "Would you like to know the sex?"

"Yes", chorused all three of them.

Jace reached out and took both his lovers' hands to squeeze them tightly, oddly nervous. "It's a girl."

Jace's heart skipped a beat. A daughter. They were going to have a daughter. Technically, they already had a daughter, they had Madzie – who was currently staying at Luke's and enjoying her borrowed grandpa. So Jace guessed they kind of knew how to deal with a girl? Maybe?

"We're going to have a daughter", whispered Jace softly beneath his breath.

Alec was squeezing his hand so tightly, Jace was pretty sure it should break any second now, while Magnus was peppering Jace's knuckles with kisses, the warlock radiating.

"Congratulations", grunted Aldertree, despite himself offering a nearly genuine smile.

/2 Months Later\

Alec frowned confused as he looked around the apartment. Jace should be home. Alec had been out with Madzie to get her a couple new clothes together with Izzy, who was honestly glad to get out of the house because the farther along Clary was, the more fussing and frantic did Simon grow. And it was kind of nice, to just be out with only his sister. Still, he had been looking forward to coming home and being greeted by his own pregnant omega (because as annoyed as Isabelle was by Simon's fussing, she too was rather protective of Clary. And Alec could understand that feeling).

"Jace? You home, love?", called Alec out loudly, sniffing the air to find the scent of his omega, just to pause because he also picked up Magnus' scent. "...You're both home? Where are you?"

"Bedroom", replied Magnus, sounding concerned.

Alec did not like that sound, especially not now that their omega was pregnant. Part of Alec was so incredibly on edge about Jace being pregnant. They had all lost so much and endured so much during the wars and somehow, Jace's biggest fear – that those he loved would be destroyed – had bled into Alec's sub-conscience. So now Alec was anxious and afraid that somehow fate would take the baby from them before it was even born, even though the rational part of Alec's mind told him that this was stupid and that not _everyone_ Jace loved was taken from him – Alec, Magnus, Isabelle, Clary, Simon, Madzie, Max, they were all around and planned on staying around.

"Mag? What's wrong?", asked Alec gently as he saw Magnus crouching in front of the closet.

He approached the warlock and once he was next to Magnus, he saw what had the alpha concerned. There, in their closet, was Jace. That in itself wasn't too rare, because Jace generally built his nest in the closet when his heat was coming up. The closet was spacious and he just had to rearrange their clothes down onto the ground where Jace, Magnus and Alec could easily fit together. Never would Alec have thought that Magnus' obsession with fashion would actually come in handy for their matebond, but the fact that Magnus had so many clothes and thus a spacious walk-in closet gave Jace a safe space for his nest. But normally omegas only nested shortly before their heat and shortly before the birth. Due to pregnancy, Jace could not go into heat and he was definitely too early for birth. Alec gulped anxiously as he snuggled up to Magnus, the warlock wrapping an arm around Alec to comfort the beta. Jace looked miserable as he was curled together in the center of the nest.

"What if I'll be a failure?", asked Jace, the scent of anxious omega filling the whole room. "I mean, look at who raised me! Valentine himself. What do _I_ know about parenting? And babies? I know nothing about babies. And Maryse and Robert were kind of not the _best_ examples of good parenting either, now were they, Alec? Didn't really teach about avoiding favoritism with the kids! What... What if I'll end up picking a favorite and then my biological daughter will grow up to resent me like Izzy resents Maryse because I picked Madzie over her and I'll be a horrible parent?"

"Yeah, that's been going on for the last half hour now", sighed Magnus, nuzzling Alec desperately. "I've already tried _everything_. He didn't let me come into the nest either. He's so busy driving himself into a frenzy, he won't accept comfort. Fix this, Alexander, you're my Jace-whisperer."

Alec would have smiled at that, if the situation wasn't actually serious, because this was the first time Jace was freaking out about this pregnancy on the account of him not being good enough for this baby. He had freaked out how Maryse and Robert would take it, he had freaked out about the general idea of being pregnant, he had freaked out about Alec's and Magnus' reaction as soon as he had found out about the pregnancy, after all. But this? Dealing with Jace's insecurities about not living up to expectations and not being good enough, that was something Magnus and Alec have been working on ever since they had become a mated threesome and it was so hard.

"Jace...", started Alec, unsure what to say to reassure his omega.

"Don't be sad, momma", whispered Madzie softly as she let go of Alec's hand to crawl into the nest and in between Jace's arms to snuggle up to the omega. "You're gonna be fine and I'll help and be a really-really good big sister for my little sister. Don't worry."

Jace stared at her wide-eyed and so did Magnus and Alec. Alec was stiffly leaning against Magnus, blinking slowly. They had officially adopted Madzie finally, but she had never called them dads or Jace mom before. The omega started purring soothingly, the scent of anxiety dissolving as he curled tightly around his adopted daughter, hugging her close.

"Thank you, buttercup, I know you'll be a great big sister", whispered Jace gently.

"So... are we allowed in too now?", asked Magnus, itching to comfort his omega.

Jace scooted over a little, allowing space for Magnus to lay behind him, while Alec went to lay on Madzie's other side, kissing her cheek. She giggled as she snuggled up to both Jace and Alec. Magnus growled pleased as he wrapped his arms around Jace's waist and buried his nose in the blonde hair, inhaling the extremely soothing scent of his pregnant omega. His hands clasped together around Jace's round stomach, caressing it tenderly.

"You okay now, Jace?", asked Alec softly, looking quizzically at his parabatai.

"Yeah", nodded Jace, small smile in place. "If I'm doing good enough that Madzie accepts me, then... I don't think I'll screw up too badly with the baby, right?"

"You're a wonderful mother and you'll be perfect for our baby too", assured Magnus.

/2 Months Later\

Magnus was pacing nervously. He had been pacing for the past hour now. At first, Alec still had cared to try and sooth his alpha, but by now he was growing more frantic himself. The only things grounding Alec were Madzie perched on his lap and Isabelle holding his hand.

"Magnus", tried Clary gently, reaching out for the warlock. "Sit down, please. Jace will be alright."

"Of course my sweetheart will be alright. And so will the little cupcake brewing inside of him, but please let me pace in peace until I get to hold my precious little princess of a daughter."

Clary looked only mildly amused, though she let the alpha continue pacing until they were allowed inside. They had started out inside – at least Magnus and Alec had – but those two _really_ couldn't behave themselves while Jace was in pain so the doctors had been forced to remove the alpha and the beta from the room. Everyone present was relieved when they were allowed back inside by a smiling nurse. Smiling was good. Clary heaved a relieved sigh, grasping Isabelle's hand to link fingers with her beta. Simon had an arm wrapped around Clary's shoulders. The threesome had left their baby daughter at Luke's when Jace went into labor.

"I can't wait to meet Dorothea's future best friend", whispered Clary eagerly.

"Stop planning our daughters' future", grunted Alec and rolled his eyes as he stormed into the room.

"Hey, sweetheart, how do you feel, my love?", asked Magnus nearly frantically.

He basically collapsed on the bed where a completely exhausted Jace was laying, gently cradling Jace's face in his hands and peppering it with kisses. At least until he heard a cry. The warlock froze and so did the others. Everyone turned toward the smiling nurse who was handing the baby over to Alec. Alec was staring at the pink bundle with wide eyes, as though he was afraid he'd drop it.

"I—I... What do I _do_?", asked Alec nearly panicky.

"For one, don't drop our daughter", grunted Jace, voice a little tired. "Come here, helpless idiot."

Alec gladly obeyed and sat down next to Magnus on the bed, looking desperately up at his mates. Clary, Isabelle and Simon lined up on the other side of the bed, with Clary gently kissing Jace's forehead. Magnus was staring at the baby in utter awe. When Alec kept looking kind of afraid of dropping the baby, Magnus decided to take the little one from his beta.

"Hello, my precious little princess. I'm your ayah, this startled deer in the headlights right here is your papa and that gorgeous, exhausted angel is your mommy", whispered Magnus gently. "Madzie, come here. Meet your new baby sister Belinda. Belinda, this is your older sister Madzie."

Madzie stared doe-eyed as she tried to climb onto the bed. Alec reached out for her and lifted her up onto his lap so she could see both Jace and the baby. Jace smiled at her in a reassuring manner.

"Hello", grinned Madzie happily, reaching out for the baby's tiny hand. "I'm your new sister."

For a while, everyone was just staring at Belinda and cooing over her. After a couple moments did Alec step back some to lean against the wall. Belinda was cradled against Jace's chest, with Madzie laying on Jace's other side, watching the baby in awe. Magnus was cooing sweet nonsense while Jace was slowly drifting off to sleep. As amazed as Alec was by it all, he was also quite overwhelmed so he took a step back and took in the view of his family curled together on the bed.

"Hey there big brother, you alright?", asked Isabelle gently as she stepped up to him.

"Y—Yeah, I just...", drawled Alec dazed, still staring at them. "We... Jace and I made a _human_. We made this perfect, beautiful little human. But... what do we do _now_?"

"You... take care of the perfect, beautiful little human", supplied Isabelle, soft smile on her face as she nudged her older brother. "You're taking good care of Madzie. You took great care of me and Maxie and Jace. You will be a great dad, Alec. Don't panic now."

"Trying", grunted Alec with a sharp nod. "It's just... a lot..."

"Alexander?", asked Magnus curiously. "Why don't you join us? We have a baby to coo over."

Alec chuckled fondly as he approached his mates again and squeezed in with his family.

/2 Years Later\

Alec did not _do_ babysitting. It was really not his thing. But Isabelle had been standing in front of the door with a charming smile and two toddlers, thrusting them into Alec's arms and declaring that she and her mates _needed_ a night to themselves and that Alec ought to fulfill his duty as best uncle because Luke had turned tail at the prospect of spending yet another weekend as babysitter – sure, Luke loved being a grandpa, but those two little Shadowhunters were exhausting and the poor man really needed a break from babysitting too. So did Alec, two hours into babysitting. Which was to equal parts ridiculous and embarrassing, considering he was a two times dad himself.

"Lexy, no, you can't eat that", sighed Alec and took the magic book from the little boy.

Lexy – or rather Lucian Alexander Lewis – turned his large, hazel-brown eyes on Alec, staring at his uncle in confusion. He was so adorable, even though he was nearly the splitting image of his father Simon, but he had the Lightwood eyes, the same gentle brown eyes as Alec and Izzy. It was what made being irritated by the toddler so hard for Alec, because Lexy reminded him a lot of Izzy.

"No eating books", chided Lexy's big sister seriously.

Well, as seriously as a two-year-old toddler could be. Alec smiled amused. Dorothea Elaine Lewis was wonderful. She _adored_ Alec, Alec was her favorite uncle and she listened to everything Alec said; so refreshing considering her mother. The tiny redhead smiled up at Alec happily.

"Clever girl", praised Alec with a smile as he ruffled her curls before pausing. "Where's Belle?"

Dorothea and Belinda were inseparable and Clary and Jace were kind of already planning their parabatai ceremony in their heads. So seeing one of them without the other was very alarming.

"Did you lose our daughter again, Alexander?", chided Magnus playfully as he entered the loft.

Alec made a face as Magnus and Jace entered the living room. Magnus had accompanied Jace to the doctor's, because after Lexy's birth and when seeing Simon, Isabelle and Clary so happy with their two babies, Jace had grown antsy and the threesome sat together to actually talk baby plans this time. Alec flushed as he took in how gorgeous his pregnant omega looked, all round and glowing.

"How's the baby?", asked Alec tensely for a second.

"Our son is healthy and perfect", assured Magnus gently before sitting down next to the beta.

"Where are our daughters though?", inquired Jace with a frown. "You did lose them, didn't you?"

"I didn't _lose_ them. They're somewhere in the apartment", grunted Alec. "...I hope."

Jace rolled his eyes a bit pointedly as he rested one hand on his belly and he inhaled deeply. "Belinda Isabelle Bane, I told you no playing hide and seek with papa _without_ telling papa!" Jace paused for a second, looking around the room with a frown. "Madison Bane, if you portaled your sister away again, you are going to be grounded for a _month_."

It took their two daughters two seconds flat to rush out of Belinda's bedroom and stand obediently in front of their parents. Magnus smiled bemused. Jace had this whole omega-of-the-house authority thing down to an art form, really. Not just with their daughters, but also with his mates. Madzie grinned sheepishly, her wild, frizzy curls pointing into every possible direction. Belinda all the while stared up at Alec with her impossibly large hazel eyes, those undeniable Lightwood-eyes, her broad blonde curls put up into two pigtails. Alec instantly melted into a puddle of parental goo, which Magnus related to, because he couldn't deny their daughters anything either. Not only did she have those wide Lightwood-eyes, no, she also had Jace's puppy-pout. Jace chuckled knowingly.

"You're a hell of a lot of trouble, Bells", grinned Jace as he knelt down in front of their daughters.

"That's why I call her Hell's Bells, mom", giggled Madzie as she sat down with Alec.

"Mommy", squeaked Belinda and jumped Jace in a tight hug. "Missed you!"

Magnus joined Madzie and Alec on the ground, easily pulling Lexy onto his lap. The littlest Lewis babbled happily, while Dorothea demanded for Alec to braid her hair. Magnus smiled gently as he looked his family over, warmth filling his heart when Jace and Belinda sat down with them too. Magnus wrapped one arm around his omega, pulling Jace against his side. The blonde hummed contently as he rested his cheek against his alpha's shoulder while watching Alec fondly. Their little family was absolutely perfect, was what Jace thought when resting a hand on his stomach.

 _~*~ The End ~*~_

* * *

 _Author's note: Obviously, this was written before the most recent episodes of the show, so with the assumption that Jace has no ties to the Herondale name. Though I'm gonna assume that by the end of the show, he actually WILL have no ties to the Herondale name anymore. It's just how this show works; Jace doesn't get to have nice things._

 _Another thing, concerning that... When I started writing this shot, I was somehow under the assumption Dot was dead. Like, for real this time. Honestly. This show needs to make up its mind. Basically every time we saw Dot, she was sooo close to death that I was like "Yup. She's a goner" and yet she keeps returning. Whatever. Let's assume she dies at a later point in the show and Clary's honoring her (but may I just mention how pissed I am that "She's like a big sister to me!" doesn't seem to give a damn about Clary anymore...? Like. At least go and visit her once and talk to her about her mom's death and all the fuck-up-ery that's happening...?)._

 _One more thing to that obligatory person who will be bothered by me having Jace be called mom: It makes virtually no sense, in a world where we assume ABO has always existed, for the terms "mom" and "dad" to be devided between "female" and "male". We got six genders. Three of them can get pregnant, will be carrying the child under their hearts for nine months. And that, that right there is kind of the definition of "mom" far beyond the "female", it just so happens that in our real world, being the one able to get pregnant and being female are kinda tied together. In an ABO-verse, it only makes sense that female betas, female omegas and male omegas fall into the "mom" category while male betas, male alphas and female alphas fall into the "dad" category._


End file.
